Although species become extinct naturally,
there is concern if human activities increase the rate of extinction. Since
humans share the environment with animals and plants, our survival depends on
maintaining a balanced ecosystem. When this balance is undermined, the effects
on plants and animals may ultimately impact the support systems human's need.
For example, it was the decline of eagles, ospreys and peregrine falcons in
the early 1970s that alerted us to the dangers of certain pollutants and insecticides
to humans.

The natural environment is comprised
of many complex relationships between plants and animals. Some are well understood,
while others are not. Think of all the complex parts you can see when you open
a computer. You may recognize some parts, but many will be unfamiliar to you.
Now imagine removing some of the unfamiliar parts. Depending on the part, you
may immediately render the computer inoperable, or the impact may not be noticeable
at first. Eventually, an impact will be realized, as the computer may not function
or perform at optimum levels. The same result can occur in the Earth's natural
systems. Although it may not be understood, all species play an ecological role(s)
and thus have an ecological value. Whether they are a producer, predator, decomposer,
or scavenger, each species has a role linked to another all the way to the top
of the food chain.

Many species may benefit humans in ways not yet discovered. Consider this:
only 2 percent of more than 250,000 plant species have been evaluated for possible
medicinal value. Once lost, the genetic information in these species is gone
forever. No matter how insignificant a species may appear, it could some day
benefit us.

The decline or disappearance of one
species may signal the deterioration of a habitat. Other species, and human
health and welfare, may soon follow. By preserving the future of endangered
and threatened species, we help preserve our own.